Phonograph pick-up apparatus



y 1930. H. A. SUMMERS El AL 1,769,902

PHONOGRAPH PICK-UP APPARATUS Original F1104 lav. 5, 1927 3 Sheets-Sheet 1 Q6 2222 A A A. Sammeza, gard A. 80 ZZe,

A A TTORNEY'.

- July 1, 1930. H. A. SUMMERS ET AL 1,769,902

PHONOGRAPH PICK-UP APPARATUS Original Filqd Nov. 5, 1927 3 Sheets-Shut 2 ATTOR/Vli July H. A. SUMMERS ET AL I 1,769,902

PHONOIGRAPH PICK-UP APPARATUS Original Filed Nov. 5, 1927 3 Sheets-Sheet 3 Ha?? A. sammez-s 574mg A. S0Z'Zz'e,

- Patented July 1, 193

HARRY A. SUMMERS, or nnooxnxn,

NEW YORK, AND SIGURD A. SOLLIE, OF PAIIO ALTO, CALIFORNIA, ASSIGNORS TO FEDERAL TELEGRAPH COMPANY, OF SAN FRAN- CISGO, CALIFORNIA, A CORPORATION OF CALIFORNIA IPHONOGRAPH PICK-UP APPARATUS Application filed November 5, 1927, Serial No. 231,374. Renewed may 8, 19301 Our invention relates broadly to electrical phonographs and more particularly to an electrical pickup device adapted to reproduce sound from phonograph records.

One of the objects of our invention is to provide a construction of electrical pick-up apparatus for electrical phonographs which is capable of manufacture and production inexpensively on a quantity production basis.

Another object of our invention is to provide a construction of electrical phonograph pick-up which is designed to reproduce accurately the ntire range of musical notes encountered in phonograph reproduction.

A further object of our invention resides in the construction of the pole pieces in an electrical phonograph pick-up device and mounting for an armature member in an electrical phonograph pick-up where the armature member is free to rock without the provision of mechanical pivots or trunnions at the ends thereof.

Other and further objects of our invention reside in the construction of an armature member for an electrical phonograph pick-up, wherein the armature member is provide with a central longitudinally extending body portion, a wedge or triangularly shaped head thereon and laterally protruding portions at opposite sides of the central body portion, the laterally protruding portions being provided with knife edges arranged to pivot upon a bearing provided in the pole face of one of the pole pieces constituting the electricfl phonograph pick-up.

Still further objects of our invention reside in the method of mounting the armature member in an electrical phonograph pickup as set forth in the following specification by reference. in which:

Figure 1 is a perspective view showing the completed electrical phonograph pick-up of our invention; Fig. 2 is a plan View of the phonograph pick-up of our invention; Fig. 3 is an end view of the phonograph pick-up of our invention illustrated partially in crosssection to show the arrangement of pole pieces and the mounting of the armature with respect thereto Fig. 4 is a side view of the cover to the accompanying drawings,.

phonograph pick-up of our invention; and

Fig. 7 is a view of the several parts constituting the electrical phonograph pickup and illustrating the relationship of the parts preparatory to the assembly process for the electrical phonograph pick-up device.

Referring to the drawings in more detail, reference character 1 designates a foundation plate structure which carries the several parts of the electrical phonograph pick-up. Upstanding lugs 2 and 3 are provided on base 1, forming trunnions for the pivotal mounting of yoke member 6 in bearings 4 and 5. The yoke 6 is secured to the end of swivel. arm 7 which is pivotally mounted upon the phonograph cabinet structure. A casing 8 is provided which fits snugly around a flanged portion of the base 1 and encloses the several parts of the electrical phonograph pick-up. A permanent magnet 9 is mounted on the d foundation plate 1 and is retained in position by means of a strip member 10 having a screw devicell passing therethrough and anchored in a screw threaded bushing 12 which is cast into the upstanding portion 14 of the base 1. The base 1 is provided with an inclined plane portion 15 extending between the poles of the permanent magnet 9. The base member 1 is apertured as represented at 16 enabling arma ture 17 to protrude therethrough. The armature 17 has an inwardly extending bore 19 with a stylus 18 secured therein for engagement with a sound record shown at 36 in Fig. 1 as carried by a record table 37. A pair of pole pieces 20 and 21 shaped as shown in Fig.

are mounted between the ends of the perma-. nent magnet 9 and have sets of pole faces directed toward each other. The pole faces are bifurcated at 20"20", and at 21 -21 The pole faces 20 are V shaped and have a non-magnetic metal central portion 20 set 20 and 21 with a rubber strip member 24.

wrapped over the wedge shaped head 22 and fittin betweenthe'pole faces 20 and 21 and the a 'ustable stops 25 and 26. These stops are s stantially-flat with inwardly extending tongues 25 and 26*, the tongues being bent atacute angles'with respect to the under surface of the plate members and provid ing' abutments ad]acent the bifurcated pole faces in slots 20 and 21 with the resilient strip 24 which extends over the wedge shaped head 22.

The resilient strip 24 serves as a cushion between the sides of the wedge shaped hea d 22 and the tongues 25 and 26. Each of the plates 25 and26 are slotted as represented at 25? and 26 enabling screw members 25 and 26 to be screwed into pole pieces 20 and 21 and adjusted with respect to the wedge shaped head 22 of the armature 17. Sets of washers 25 and 26 are positioned wit-h the heads of screws 25 and26 and the plate members 25 and 26. The electromagnetic winding is shown in the form of a bobbin 28 wound upon the insulated support 27 which fits between the pole members 20 and 21 as illustrated with the sets of pole faces at opposite ends of the electromagnetic winding. The armature member 17 passes through the electromagnetic winding 28 and has the wedge shaped head 22 thereof engaged on opposite sides by theresilient strip 24. The laterally protruding portions'of the armature are provided with knife edge faces 17 and 17 which engage the. bearing member 20 in the V- shaped faces 2O of the pole member 20. The opposite faces of the laterally protruding portions of the armature are circular as indicated at 17 and 17 conforming with the shape of the pole faces 21. A resilient strip 23Y is seated between the rounded faces 17 and 17 which are spaced from the rounded faces 21 of pole piece 21 by means of resilient strip 7 i 23. Rocking movement is imparted to the armature by the stylus 18 and torsional stresses occur in the resilient strip 23 as the rounded faces 17 and 17 d tend to move the entire mass of the resilient strip 23 by shearing forces which are resisted by the inherent structure of the resilient strip .23. A screw device 29 extends into the end of the armature member and secures the stylus 18 in the recess 19 in the armature 17. Electrical conductors 32 extend 'from the electromagnetic winding 28 to the lug members 83 and33 of binding posts 33 which are carried by terminal block 31 on the foundation plate structure 1. Flexible leads 30' extend from the binding posts. 33 on the terminal block 31 through the hollow arm 7 to the input circuit of the amplification system constituting the has proven highly eflicient in operation and ractical in its construction, and while we have described a preferred embodiment of the invention, we desire that it be understood that modifications may be made and that no limitations upon our invention are intended other than are imposed by the scope of the appended claims.

\Vhat we claim as new and desire to secure by Letters Patent of the United States is as follows: i

1. An electrical phonograph pick-up comprising a foundation plate arranged to lie in a plane substantially parallel to a phonograph record during the movement of the pick-up over the record, an inclined plane member at (inc end of said plate, a pair of pole members mounted on said inclined p ane member and directed toward each other laterally with respect to said plate, an armature mounted for swinging movement between said pole members in a plane passing through the longitudinal axis of said plate, and means at the opposite end of said plate member for pivotally supporting said phonograph pick- 2. An electrical phonograph pick-up comprising a foundation plate, an inclined plane member at one end of said plate, a permanent magnet carried by said plate member and extending on opposite sides of said inclined plane member, an electromagnetic winding, a pair of pole pieces mounted on said inclined plane and directed toward each other, said pole pieces having faces extending on opposite sides of said electromagnetic winding, one of said pole faces being arcuate in shape and the opposite pole face being V shaped, and an armature member having a rounded face at one side and knife edge contact faces at the opposite side with the knife edge of said armature member in engagement with said V shaped pole'face, and resilient means between the rounded face of said armature member and the arcuate shaped pole face.

3. An electrical pickup comprising a foundation plate member arranged to lie in a plane substantially parallel to a phonograph record during the movement of the pick-up over the record, an inclined plane at one end of said foundation plate member, a permanent magnet carried by said plate member and extending on opposite sides of said inclined plane, pole pieces carried by said inclined plane and directed toward each other, one of said pole pieces having a V shaped face, an armature member, a nonmagnetic insert within said V shaped face providing a bearing for said armature member and means at the opposite end of said plate member for pivotally supporting said phonograph pick-up.

thepick-up over the record, a terminal-block at one end of the plate member, an inclined platform at the opposite end of the plate member, a permanent magnet carried by said plate member and surrounding said platform, a pair of pole pieces fitted on saidv inclined platform and extending between the poles of saidpermanent magnet, an electromagnetic winding disposed between said pole pieces, an armature member rockable within said electromagnetic winding and driven by a stylus connected with said armature member and means on said plate member on opposite sides of said terminal block for pivotally supporting said phonograph pick-up.

5. In an electrical phonograph pick-up, an

j armature having a vertical central portion,

a triangularly shaped head thereon, adjustable members on opposite sides of said triangularly shaped head for damping the movement of said armature, laterally extending portions on said armature, rounded faces at one side of said laterally extending portions and knife edges at opposite sides of said laterally extending portions.

6. In an electrical phonograph pick-up, a. foundation plate member arranged to lie in a plane substantially parallel to a phonograph record during the movement of the pickup over the record, an electromagnetic actuator carried by said foundation plate member, an electromagnetic winding, an armature pivotally mounted within said electromagnetic winding, pole members surrounding said electromagnetic winding, the pole members being bifurcated at their upper ends and aligned with respect to each other, adjustable plate members having tongues disposed at an angle to theplane of said plate members, a triangularly shaped head on said armature, a resilient member disposed between the sides of the triangularly shaped head and the tongues on said plate members and means adjacent one end of said plate member for pivotall y supporting said phonograph pick-up.

. 7. In an electrical phonograph pick-up, a foundation plate member, an electromagnetic winding carried by said plate member, an

armature member positioned within said windmg, a pair of pole members havlng b1- furcated pole tips directed toward each other, the upper set of pole tips being cut at an angle with respect thereto for resiliently damping the movement of said armature member and the lower set of pole tips having a pair of concave faces with the opposite pole tip having a pair of V shaped faces, said armature member having a pair of knife edges cooperating with the V shaped faces on one of the pole tips, and a rounded surface record during the movement of the pick-up over the record, means located centrally of said plate member for retaining a permanent magnet in horizontal alignment thereon, an inclined plane adjacent one end of said plate member and between the poles' of said permanent magnet, pole pieces secured to said inclined plane and directed toward each other between the poles of said permanent magnet, an electromagnetic winding, an armature member rockably mounted in said pole pieces and passing through said plate member substantially perpendicular to said inclined plane, a stylus carried by said armaure memher for imparting movement to said arature member from a sound record for effeczing variable displacement of said armature wiih respect to said electromagnetic winding and means adjacent .the opposite ends of said plate member for pivotally supporting said phonograph pick-up. a 9. An electromagnetic translating device comprising, a base member,- a permanent magnet carried by said base member, a pair of pole pieces bet-ween the poles of said permanent magnet, an inclined member on said base member adjacent one end thereof, means for mounting said pole pieces on said inclined member, an armature movable between said pole pieces, and a stylus carried by said armature, said armature being mounted so that said stylus is substantially perpendicular to said inclined member, whereby when said base member is in parallel relation to a phonograph record said stylus is disposed'at an angle to said phonograph record.

10. An electromagnetic translating devlce as defined in claim 9 and means for rotatably mounting said base member at the end thereof opposite said inclined member;

In testimony whereof w'e aflix our signams HARRY A. SUMME, RS.

SIGURD A. SOLLIE. 

